Tag Archives: domestication

Puppies understand human gestures from an early age with no training unlike wolf pups

The Duke Canine Cognition Center’s Puppy Kindergarten Spring 2020 class photo. The seven puppies, from Canine Companions for Independence, are part of a long-term study funded by the National Institutes of Health to assess the effects that different rearing strategies have on the behavior and cognitive development of assistance dogs. Credit:  Jared Lazarus.

Dogs can understand and respond to human communication from a very early age and with virtually no training, unlike other domesticated species. You might not think much of it when you play fetch with your dog, but this simple act of communication and coordination is a pretty big deal from both a cognitive and evolutionary standpoint. This suggests that the strong bond between humans and dogs has led to co-evolved traits that have turned dogs increasingly social towards us. In a new study, researchers at Duke University argued in favor of this notion, after showing that wolf pups could not understand human gestures meant to help them find tasty treats, whereas dog puppies aced the test despite having no training.

“It was important to us to test puppies, not just adult dogs and wolves, because we wanted to see whether there is an innate species difference, which cannot be explained solely by learning over life experience,” Hannah Salomons, a doctoral student at Duke University, told ZME Science.

“The main finding of this study is that compared to wolf puppies, dog puppies have high levels of social skills that allow for cooperative communication, such as understanding that a human gesture is meant to help them find hidden food. The dog puppies were also far more attracted to humans, and would approach both strangers and familiar people more often than the wolf puppies. However, on non-social tasks, the dog and wolf puppies performed similarly,” she added.

The gestures of domestication

Wolf puppies at Wildlife Science Center in Minnesota, where the testing took place. Credit: Roberta Ryan.

Dogs and wolves share close ancestors and researchers have been studying their similarities and differences for years, hoping to deconstruct the origins of canine domestication. Previously, scientists had compared dog and wolf social abilities, showing that dogs seem to have an innate ability to respond to human-given cues such as pointing gestures whereas wolves need special training.

The new research at Duke University is similar in scope to other studies, but with a much higher sample size of cute puppies and adorable pups. While other studies used at most 12 puppies of each species, this time the researchers worked with three dozen puppies per species, which offers much better confidence in the statistical significance of the findings. The wolf young were also genetically tested in order to confirm that the puppies were indeed wolves and not some dog hybrid, something no previous such study verified before.

The 37 wolf puppies were raised at the Wildlife Science Center in Minnesota where they were surrounded and cared for by humans almost round the clock. But despite the ubiquity of human interaction, the wolf pups were still very shy and would only come out of hiding when in the presence of caretakers they knew well. In contrast, the 44 puppies from Canine Companions for Independence spent most of their time in the company of their mothers and littermates and had minimal human contact when they were enrolled in this study.

“Being able to test such a large sample of wolf puppies was a huge undertaking, that took our team over six years to complete – only a few litters are born at Wildlife Science Center per season, and despite being raised by humans round-the-clock from just a few days old (which, I should note, is part of WSC’s typical husbandry practice, not done for the purpose of this study, and is a huge feat in and of itself), some of the wolf puppies are so shy around people that they never warm up to the experimenter enough to participate in the study. I have some great memories of sitting in the wolf pup enclosure for hours at a time, seeing them go from hiding when I first entered to frolicking and playing as they acclimated to my presence, and being rewarded with one pup dragging over a nice ripe piece of deer carcass (her favorite food) to sit next to me and gnaw on!” Salomons said.

In order to assess their communication skills, the young canids were pitted against each other in a series of tests. During one such task, the dog and wolf puppies had to find a treat hidden beneath one of two bowls. To help them out, the researchers pointed and gazed towards the correct location of the stashed food. In other tasks, a human planted a small wooden block beside the right spot to indicate where the food was hidden, a gesture that neither of the two types of pups had seen before.

The results spoke for themselves. Despite their lack of formal training, 17 out of 31 dog puppies consistently went to the right bowl, whereas none of the human-reared wolf pups performed better than a coin toss. Subsequent trials showed that the puppies were guided by human gestures rather than the odor of food.

Many of the puppies completed their trials on their first go, which suggests that this remarkable ability is hard-wired in the dogs’ brains. But that’s not to say that dogs are smarter than wolves. Chimps, our closest relatives along with bonobos, can’t read human gestures, although they’re much better than dogs at complex cognitive tasks.

All pups are good boys and girls

Canine Companions for Independence puppies at the Duke Puppy Kindergarten. Credit: Jared Lazarus.

Evolution does not produce species that are ‘better’ or ‘worse’ than others but rather fosters species that are most adapted to their environment. Both canids have more or less the same cognitive abilities in terms of memory and motor impulse control. It’s just that puppies have much better people skills due to their close proximity to our species for thousands of years.

Emily Bray of the University of Arizona and colleagues showed in a 2021 study that puppies as young as eight weeks can understand instructions from humans, such as finger-pointing and gazing towards an object. This study found that 40% of the variation in a puppy’s ability to follow a human’s finger-pointing or gaze can be explained genetically, which makes sense in light of other findings. We know from previous research that breeds of dogs that were initially selected for cooperative work (like sheepdogs) are much better at following a person’s point than breeds selected for other kinds of work like guard dogs, hounds, or sled dogs).

This familiarity and strong bond with humans is perhaps best evidenced by how wolf and dog puppies differ in the way they respond to strangers. Tests showed that dog puppies were 30 times more likely to approach a stranger than the shy wolf pups.

Previously, researchers in Austria and Hungary also assessed wolf and dog pups’ ability to follow human gestures. They found that dogs as young as four months of age understand pointing gestures to find hidden food even without intensive early socialization. Wolf pups, on the contrary, do not attend to this subtle pointing. Interestingly, this particular study found that wolves socialized at a comparable level to dogs are able to use simple human-given cues spontaneously if the human’s hand is close to the baited container (e.g. touching, proximal pointing). The wolves also responded to gestures pointing to objects at a distance if they received formal training. This isn’t that surprising considering how closely related the two species are, but the effects of domestication on people’s skills are quite striking.

“The evidence from this study along with many others makes it very clear that dog puppies can understand humans’ cooperative communicative gestures from a young age, without any explicit training or intensive human experience,” Salomons said.

“As for why other domesticated animals may not show the human-like cooperative communicative ability seen in dogs, this is likely to be constrained by the pre-existing social cognitive abilities of their wild predecessors.  As wolves already had fairly complex social skills, as the domestication process progressed and an attraction to humans replaced fear, they were able to apply these skills in new ways and they began to emerge earlier in development.  Other species, such as the wild predecessors of sheep or cattle, may not have had similar starting levels of social skills for the domestication process to shape. Even so, evidence is coming out that in other species, such as ferrets, domesticated populations do outperform wild populations at reading human gestures!”

Credit: Roberta Ryan.

According to Salomons, these findings show that domestication, by selecting for attraction to humans, altered dogs’ social development, resulting in the remarkable cooperative-communicative abilities we see today. Scientists aren’t exactly sure how all this happened, but perhaps it all started with a few wolves that were unusually friendly towards humans and that received food scraps in return for their non-aggressive behavior. Over time, wolves that were friendly towards humans had a better chance of reproducing and passing on their ‘tamed’ genes whereas wolves that were fearful and aggressive towards humans stayed to themselves. After hundreds of generations, this common ancestor speciated into Canis familiaris, the faithful canine we all love and cherish.

“This knowledge is important because understanding how dogs’ minds are wired can help us learn to communicate with them better and work together as a stronger team. Also, a similar process, known as self-domestication, may have occurred over the course of human evolution as well, so understanding its effects may shed light on the development of our own minds,” Salomonds concluded.

In the future, the researchers plan to perform a longitudinal study that charts the temperament and performance of individual puppies on social and non-social cognitive tasks to see how these different cognitive aspects develop and change over time and how they interact with one another.

The findings appeared in the journal Current Biology.

Why zebras were never domesticated

Woman riding a tamed zebra named Bromar in 1923. Credit: Public Domain.

Zebras are more than just horses with stripes, which was something that European colonists would find out the hard way after countless failed attempts to domesticate them. While a few zebras were tamed here and there in the 18th and 19th centuries, as one can witness in historical photos showing zebras pulling carts or people riding them, it proved too much work and any subsequent effort to harness zebras for work alongside humans was abandoned.

Like horses and donkeys, zebras belong to the Equidae family (known as equids). The three species are so closely related that they can interbreed and form hybrids such as a zedonk (a cross between a male zebra and a female donkey), a zorse (the offspring of a male zebra and a female horse), and zonie (hybrid between a zebras and ponies). But unlike their cousins, zebras resisted submitting to humans. Why is that? After all, zebras are native to Africa, the cradle of humanity.

It may all have to do with natural selection. Zebras and horses diverged from a common ancestor around 4-4.7 million years ago, and each became adapted to their particular environments. Herds of wild horses in North America and Europe were initially kept as food animals, but later became accustomed to humans. After the advent of agriculture 12,000 years ago, horses proved their worth in transportation and warfare, which prompted humans to invest time and effort into domesticating them by selectively breeding the tamest individuals.

A zonky: half zebra and half donkey. Credit: Ruth Boraggina/Wikimedia Commons.

But unlike wild horses, zebras in the open African savanna had many more predators to worry about, including fierce lions, lightning-fast cheetahs, and cunning hyenas. As such, natural selection forged zebras into very reactive animals that are ready to leap at the slightest sign of danger. Zebras are particularly feisty and will greatly resist getting captured.

Despite their poney-like size, some zebras have managed to kill attacking lions with a single back kick. They’re not less menacing from the front either, as they’re known to pack a savage bite. Zebras also have a hardwired ducking reflex, which greatly hinders their capture by lasso or other methods. Finally, zebras have no family structure and no hierarchy, unlike wild horses that live in herds and have a structured order.

People quickly recognized these highly unfriendly qualities, but they nevertheless tried to break the zebra to harness. For instance, in the 19th century, George Grey imported zebras from South Africa to New Zealand, where he was newly appointed governor and was fond of having a carriage pulled by the wild african equids. Victorian-era zoologist Lord Walter Rothschild famously drove a carriage drawn by zebras to Buckingham Palace. Later, in the early 20th century, Rosendo Ribeiro, the first doctor in Nairobi, allegedly made house calls on zebraback.

Lord Walter Rothschild, of the infamous Rothschild banking family, riding a carriage pulled by zebras. Credit: Public Domain.

The German army in its German East Africa colony was particularly interested in domesticating zebras in lieu of horses. They even implemented a program to cross zebras with horses to create hybrids that were resistant to disease that typically wiped out imported horses.

German colonial officer riding a tame zebra jumping a fence in East Africa.  Photo taken between 1890 and 1923. Credit: Prints & Photographs Division, Library of Congress.
A German soldier riding a zebra in Zanzibar, German East Africa, in the 1890s. Credit: Public Domain.

However, these were just a couple of instances of tamed individuals. Overall, zebras proved too stubborn to domesticate, despite the best efforts of European colonists in Africa who would have made good use of them. Even recent efforts have proven somewhat futile. In 2013, a teenager in Virginia, Shea Inman, trained a zebra to ride it. After many months of patience and reward-based training, she managed somewhat to ride the zebra, although Inman noted: “Some days it’s like he’s been riding for 30 years and other days he acts like he’s never seen a human being.”

So despite their horse-like appearance, zebras won’t submit easily to humans. They like to live life as nature intended: always on their own terms.

Algae-farming fish domesticate shrimp to improve their farms

Longfin damselfish. Credit: Griffith University.

Domestication changed human history forever. Judging from mitochondrial DNA, scientists believe that the dog was the first animal to be domesticated nearly 14,000 years ago from wolves. Later, came farm domestications, including animals such as sheep, goats, pigs, and cattle. But humans aren’t alone in this game.

According to a fascinating new study by Australian researchers, longfin damselfish (Stegastes diencaeus) have domesticated mysid shrimp (Mysidium integrum), whose feces is a good fertilizer for the algae that the fish farms.

“Domesticator-domesticate relationships are specialized mutualisms where one species provides multigenerational support to another in exchange for a resource or service, and through which both partners gain an advantage over individuals outside the relationship. While this ecological innovation has profoundly reshaped the world’s landscapes and biodiversity, the ecological circumstances that facilitate domestication remain uncertain,” the authors wrote in their study published in Nature Communications.

“Mysids passively excrete nutrients onto farms, which is associated with enriched algal composition, and damselfish that host mysids exhibit better body condition compared to those without,” they added.

When researchers at Griffith and Deakin Universities first observed this behavior during dives to coral reefs in Belize, they almost couldn’t believe it. It wasn’t some fluke or misunderstanding either, as subsequent lab tests confirmed that damselfish were indeed in a domesticator-domesticate relationship with the shrimp.

Mysid shrimps benefit from the protection provided by damselfish and, in turn, improve the condition of the farmer, the damselfish. Credit: Griffith University.

The researchers found that the mysids are attracted to the odor of the damselfish, but are repelled by the smell of predators. The mysids also don’t seem to be attracted to non-farming fish nor the algae itself.

When the shrimp were around, the quality of the algae and the health of the fish improved. In return for the shrimp’s fertilization of their farm, the fish actively protect the mysids. The researchers found that outside the algae farms, other fish tried to eat the shrimp, but inside the farm under the watchful eyes of the damselfish, predators didn’t come close.

“This is not unlike the series of theoretical steps underpinning the domestication of animals by our own ancestors via the commensal pathway, where animals who were attracted to human settlements were subsequently domesticated by ancient humans,”  Dr. William Feeney from Griffith University’s Environmental Futures Research Institute and co-author of the new study, said in a statement.

“It is generally food scraps or shelter that are thought to have attracted animals to humans.”

The domestication of other species was long considered to be uniquely human. While we know of ants that have domesticated fungi, finding examples of animal domestication by species other humans has proven elusive thus far. So, in many ways, seeing another species performing its own domestication may tell us much about how we first domesticated familiar species like cats, dogs, and chickens.

“This study highlights the important role that protection from predators also plays in domestication, with mysids shrimp quickly consumed by other predators when the damselfish farmer wasn’t present,” Feeney said.

“It reveals the fascinating insights into domestication by humans that can be gained by examining relationships between non-human organisms.”

Baby wolves like to play fetch too — what this says about your dog

Playing a game of fetch with a dog means they are following a human social cue to recover the ball. But fetch isn’t just for dogs, wolf puppies are down to play too, which means they can also understand human communication cues, according to a new study.

Credit Wikipedia Commons

The findings, published in the journal iScience, were made after researchers put 13 8-week-old wolf puppies from three different litters through a series of tests usually used to assess dog-puppy behavior. Three of the pups were interested in playing fetch with a stranger, which included bringing a ball back when encouraged to.

The discovery was quite a surprise for the team as it was believed that the cognitive abilities necessary to understand communication cues given by a human were presented in dogs only after humans domesticated them 15,000 years ago. Dogs differ from wolves physically, genetically and behaviorally.

“When I saw the first wolf puppy retrieving the ball, I literally got goosebumps,” said Christina Hansen Wheat of Stockholm University in a press release. “I immediately knew that this meant that if variation in human-directed play behavior exists in wolves, this behavior could have been a potential target for early selective pressures exerted during dog domestication.”

Wanting to learn more about the effects of domestication on behavior, Hansen Wheat and her team raised wolf and dog puppies from the age of 10 days and put them through various behavioral tests. In one of them, the pup was thrown a ball by an unknown person, encouraging the wolf to get it and bring it back.

Expectations of the wolf pups catching on weren’t high, with the first two litters showing no interest in the balls, let alone of playing fetch. But everything changed with the third litter. A few of the puppies went for the ball and even responded to the social cues and brought it back.

“It was very surprising that we had wolves actually retrieving the ball,” said Hansen Wheat. “I did not expect that. I do not think any of us did. It was especially surprising that the wolves retrieved the ball for a person they had never met before.”

In the past, other research showed that domesticated and non-domesticated species will follow human gestures if a food reward is given, Hansen Wheat and her team said. But in those cases, the animals were previously trained to follow the cues or knew the person conducting the study.

While the new research has a limitation over the size of its sample, it could reassess our interpretation that understanding human social cues came from domestication. Instead, it could be possible that this behavior can be traced back to an ancestral population before wolves were domesticated into dogs.

We have the first genetic evidence of human self-domestication

New research at the University of Barcelona (UB) found the first genetic evidence that humanity has self-domesticated.

Comparison of Modern Human and Neanderthal skulls from the Cleveland Museum of Natural History.
Image credits DrMikeBaxter / Wikipedia.

The team found a network of genes involved in the evolution of human face structure and prosociality in modern humans which is absent in the Neanderthal genome. This suggests that our ancestors preferred to hang out and mate with friendlier and more cooperative companions over less-cooperative, more aggressive ones. In effect, this amounted to selective pressure for prosocial behavior over time, meaning that we domesticated our own species.

Our own best friend

Certain anatomical, cognitive, and behavioral traits of modern humans — chief among them docility and a fragile facial structure — are hallmarks of the domestication process. This led to the idea of human self-domestication being developed all the way back in the 19th century, the team explains. However, we lacked the tools to confirm that this process took place (i.e. that there’s genetic evidence for it).

The study builds on the team’s previous research that looked into genetic similarities between humans and domesticated animals. Now, the team went one step further and looked for genetic evidence for self-domestication in neural crest cells. This is a population of cells that have a major role to play in the early development of vertebrate embryos by differentiating into more specialized cells.

“A mild deficit of neural crest cells has already been hypothesized to be the factor underlying animal domestication,” explains co-author Alejandro Andirkó, a Ph.D. student at the Department of Catalan Philology and General Linguistics of the UB.

“Could it be that humans got a more prosocial cognition and a retracted face relative to other extinct humans in the course of our evolution as a result of changes affecting neural crest cells?”

In order to test their hypothesis, the team focused on Williams syndrome disorder, a human-specific neurodevelopmental disorder caused by a deficit of neural crest cells as the embryo develops. It is characterized by mild to moderate intellectual disability or learning problems, unique personality characteristics, distinctive facial features, and cardiovascular problems.

The researchers used in vitro models of Williams syndrome (stem cells derived from the skin of patients with this syndrome). After poking around, they found that the BAZ1B gene, conveniently located in the region of the genome associated with Williams syndrome, is responsible for controlling the behavior of neural crest cells. If this gene was under-expressed, it led to reduced migration of these cells; higher expression levels led to greater neural crest migration. Then, they compared this gene to its equivalent in samples of archaic (i.e. extinct) and modern (i.e. our ancestors’) human genomes.

“We wanted to understand if neural crest cell genetic networks were affected in human evolution compared to the Neanderthal genomes,” says Cedric Boeckx, ICREA professor at the Department of Catalan Philology and General Linguistics.

Differences in the BAZ1B gene between archaic and modern humans led to a high frequency of mutations in that accumulated over time in modern humans — but not in any of the archaic genomes currently available. The team says this points to BAZ1B as being “an important reason our face is so different when compared with our extinct relatives, the Neanderthals.”

“In the big picture, it provides for the first-time experimental validation of the neural crest-based self-domestication hypothesis,” Boeckx adds.

The paper “Dosage analysis of the 7q11.23 Williams region identifies BAZ1B as a major human gene patterning the modern human face and underlying self-domestication” has been published in the journal Science Advances.

Grazing animals drove the domestication of grain crops

Large grazing animals have a strong selective force on plants, certain plants have evolved traits to thrive on pastoral landscapes. In the Himalayas, yaks (such as the one depicted here) were a significant evolutionary driver. Image credits: Robert Spengler.

In the history of mankind, few things have been as influential as domestication. Whether it’s plant or animal domestication, this process has enabled our species to lay the foundation of what we now call society. Having access to a reliable source of nutrients enabled settlements to develop and thrive.

The earliest known human attempts at plant domestication occurred in the Middle East, some 11,000 years ago. However, the domestication of grain plants became much more common 7,000-5,000 years ago, in river valleys and grasslands all around the world. That process was driven by the domestication of grazing animals, a new study concludes.

It’s not exactly surprising. It’s been known for quite a while that many familiar grains have common traits suggesting that they coevolved to be dispersed by large grazing mammals. Essentially, the changes in the plant biomes were driven by changes in animal behavior — which themselves were driven by domestication.

Robert Spengler, director of the Paleoethnobotany Laboratories at the Max Planck Institute for the Science of Human History, and Natalie Mueller, a National Science Foundation fellow at Cornell University, write that the progenitors of small-seeded crops evolved to be dispersed by domesticated animals. They looked at the herbivory patterns and the rangeland these herbivores would have inhabited. Although these wild varieties now only grow in isolated patches, these patches are much more common near rivers or other areas that animals were more likely to frequent. Growing in patches also made harvesting them easier for early human populations.

The study was carried out in North America, where, for a long time, the domestication of plants wasn’t well understood. The missing puzzle piece was bison. As the massive bison herds moved throughout North America, they dispersed these plants in relatively compact areas, leaving a trail of vegetation behind them. But as the European populations slaughtered the bison, the plant populations also started to dwindle.

[Also Read: How megafauna and humans shaped the apple’s domestication]

Bison herds, once dominant across many areas of the US, are now functionally extinct. Image via NPS.

However, this process wasn’t restricted only to North America. Elsewhere in the world, other grazers also helped spread certain plant populations, something which humans took advantage of. As domesticated animals became more and more common, they also played a selective role.

“Small-seeded annuals were domesticated in most areas of the world,” explains Spengler. “So the ramifications of this study are global-scale. Scholars all over the world will need to grapple with these ideas if they want to pursue questions of domestication.”

For decades, researchers have debated why early human foragers preferred small-seeded annual plants as a major food source (which ultimately led to their domestication). The fact that these plants would have been easy to harvest and preferable by animals probably contributed to their ultimate domestication.

Now, researchers want to further analyze this idea and see how other ruminant megafauna contributed to the distribution and domestication of plants all around the world.

“Currently, we’re studying the ecology of fields where modern herd animals graze as proxies to what the ecology would have looked like during the last Ice Age, when large herds of bison, mammoths, and wooly horses dictated what kinds of plants could grow across the American Midwest and Europe,” explains Spengler. “We hope these observations will provide even greater insight into the process of domestication all over the world.”

The study was published in Nature Plants.

Credit: lifewithcats.tv.

Viking cats show that domesticated felines have grown bigger in time (as well as a gruesome history)

Credit: lifewithcats.tv.

Credit: lifewithcats.tv.

Domesticated animals are usually smaller in size, have fewer teeth, and fewer or less pronounced defense adaptations, such as horns. Dogs, for instance, are about 25% smaller than gray wolves, while other domesticated animals, such as chicken or sheep, are so dependent on people they could barely survive without us. But cats seem to be an exception — in terms of size at least.

Researchers at the University of Copenhagen studied hundreds of feline bones from the time of the Iron Age, Vikings, and Middle Age, and then compared them to modern house cats. The results suggest that cats grew by about 16% between the Viking Age and today. The study also has a darker side to it. According to the findings, some cats were clearly skinned by Vikings, who likely used the pelts to fashion clothing and traded them for other commodities.

Cat history

Cats’ long journey to today’s internet adoration started some 9,000 years ago, according to a 2017 genome-wide analysis. Cat populations seem to have grown in two distinct waves. First, Middle Eastern wildcats expanded with early farming communities to the eastern Mediterranean some 9,000 years ago. Presumably, newly founded grain stockpiles became infested with rodents and cats helped purge the pests earning their keep alongside humans.

It’s not clear when cats became domesticated but the Egyptians might have had the first some 6,000 years ago. From Egypt, the felines rapidly expanded across the rest of Africa and Eurasia. Cats spread to Europe as early as 4,400 B.C, but it wasn’t until much later that the felines arrived in Scandinavian countries, brought by seafaring people.

Viking cat skulls (upper right corner) compared to modern cat skulls (lower right corner). Credit: Anne-Birgitte Gitfredsen.

Viking cat skulls (upper right corner) compared to modern cat skulls (lower right corner). Credit: Anne-Birgitte Gitfredsen.

The researchers at the University of Copenhagen analyzed countless bones collected from various archaeological sites across Denmark. The remains cover almost 2,000 years of feline history, from the late Bronze Age and ending in the 1600s. Many of these bones were sourced from pits where Vikings disposed of the dead cats… after they had removed their fur, judging from clear cut marks on the bones.

By comparing the remains to modern Danish cats dating from the 19th century to the present day, the researchers concluded that domesticated cats grew by about 16% since the Viking age. Since only remains from sites in Denmark were included in the study, it may be too early to draw generalized conclusions.

Cats may have grown bigger due to more access to food, particularly rodents who were attracted by mounting waste and food supplies in expanding settlements. Broiler chickens, for instance, are two times bigger than they were in medieval times. In time, cats became well fed because humans started cherishing them, feeding them some of their own food. It’s not clear, however, whether cats are bigger today because they eat more or due to some genes that make them plumper. This is something that a new study in the future might answer.

The findings were reported in the Danish Journal of Archaeology.

A) An Afroalpine rodent among geladas (Theropithecus gelada); B and C) Ethiopian wolves (Canis simensis) foraging for rodents among geladas; and D) an Ethiopian wolf successfully captures a rodent while among geladas. Credit: Journal of Mammalogy.

Monkeys and wolves forge alliance that resembles domestication done by humans

A) An Afroalpine rodent among geladas (Theropithecus gelada); B and C) Ethiopian wolves (Canis simensis) foraging for rodents among geladas; and D) an Ethiopian wolf successfully captures a rodent while among geladas. Credit: Journal of Mammalogy.

A) An Afroalpine rodent among geladas (Theropithecus gelada); B and C) Ethiopian wolves (Canis simensis) foraging for rodents among geladas; and D) an Ethiopian wolf successfully captures a rodent while among geladas. Credit: Journal of Mammalogy.

In the grasslands of Ethiopia, scientists were amazed to find a striking example of inter-species collaboration. Ethiopian wolves were seen casually strolling among herds of gelada monkeys, which you would expect to flee out of the way of such a predator. But it seems like the monkeys tolerate the wolves in their presence and are not frightened by them. The wolves, on the other hand, ignore the geladas’ potential as meals, preferring to linger around the herd because it helps them catch more rodents. This odd relationship resembles the ancient domestication of dogs or cats by humans, some researchers say.

Live and let live

Gelada monkeys (Theropithecus gelada) look a lot like baboons. These primates are known to live in close-knit family groups, but can also live as part of shockingly vast communities consisting of hundreds of individuals. They live peacefully even in the most numerous communities, a relatively rare achievement in the wilds of Africa.

Geladas are graminivores, meaning their diet consists of 90% grass. Essentially, they’re the only living primates that subsist almost entirely on grass, a trait more commonly seen in ungulates like deer and cattle.

While the primates congregate in huge herds, munching on grass for hours upon hours, the shrewd (and endangered) Ethiopian wolf (Canis Simensis) mingles with the geladas. Usually, the wolves travel in zig-zag, sprinting when they sense prey is within their grasp. But, around the geladas, the wolves roam casually, being careful not to startle the herd.

Researchers at Dartmouth College observed the dynamics between the species for a new study. They conclude that the Ethiopian wolf is not interested in geladas for food, although they have no qualms hunting juvenile sheep and goat. The monkeys seem to know this, as they don’t seem to feel threatened in the predators’ presence. But why is that?

After following Ethiopian wolves for 17 days, the researchers found that those individuals which hunted rodents within a gelada herd were successful 67% of the time, compared to a success rate of only 25% when they prowled on their own. The findings were reported in the Journal of Mammalogy.

“For Ethiopian wolves, establishing proximity to geladas as foraging commensals could be an adaptive strategy to elevate foraging success. The novel dynamics documented here shed light on the ecological circumstances that contribute to the stability of mixed groups of predators and potential prey,” wrote the authors of the new study.

For now, it’s not clear what makes the wolves more successful when hunting within gelada groups. The monkeys might be flushing out rodents from their burrows due to their insistent grazing, but that’s just an unverified hypothesis at the moment. Alternatively, the monkeys might be providing cover for the wolves, distracting the rodents from the dangerous predator.

The Ethiopian Wolf -- also known as ‘ky kebero’, which means red jackal -- is one of the rarest and most endangered of all canids. Credit: Wikimedia Commons.

The Ethiopian Wolf — also known as ‘ky kebero’, which means red jackal — is one of the rarest and most endangered of all canids. Credit: Wikimedia Commons.

Sometimes, a wolf will attack a gelada young. During one instance when this happened, the other monkeys in the herd quickly attacked the wolf, forcing it to drop the infant. After the wolf was driven away, it was never allowed in the midst of the herd again. Other individuals seem to understand this dynamic very well and will resist the temptation of grabbing a quick gelada meal in favor of the prospect of better dividends in the long run.

The researchers say that the Ethiopian wolf might be hanging around other species, such as cattle, to hunt more rodents. It’s also possible other predator species may be doing something similar without us finding out about it yet.

What’s intriguing is that the gradual toleration between the two species is very similar to the domestication process performed by humans on dogs. The first wolves began to be domesticated by humans sometime between 40,000 and 11,000 years ago, but the details pertaining to how this happened are not clear. According to one hypothesis, wolves started hanging around humans, who would leave large carcasses behind them after each big hunt. Gradually, the two species became more accustomed to one another. Later, wolves may have helped humans on the hunt, cementing the relationship between the two.

Could the same thing be happening in Ethiopia’s grasslands? Given a couple thousand of years, could we see geladas with wolves as pets? That would be quite the sight — but it’s rather unlikely. The monkeys don’t seem to derive any benefit from tolerating the wolves in their presence, and without a two-way value exchange between the two species, domestication won’t likely happen.

What’s more, the Ethiopian wolf might become extinct soon before there’s any reasonable time for domestication to play out. Researchers estimate that there are only 450 adult Ethiopian wolves left in the wild. Continuous loss of habitat due to high-altitude subsistence agriculture represents the major current threat to the Ethiopian wolf.

Ground cherry

In a just a few years, scientists could domesticate the delicious ground cherry

Move over, strawberry — there’s a new berry in town that Millenials are drooling over. Using state-of-the-art gene editing, researchers claim they’ve come close to domesticating the groundcherry, a wild berry native to Central and South America. Instead of waiting for decades or even thousands of years to domesticate the berry through conventional methods, the scientists say that their approach could bring this highly-sought-after food to supermarket shelves around the world much faster.

Ground cherry

Credit: Pixabay.

The ground cherry (Physalis pruinosa) is classed as an orphan crop — minor crops, which also includes tef, finger millet, yam, roots, and tubers, that tend to be regionally important but not traded around the world. The reason why such foods are rarely traded internationally is due to their poor shelf life and low productivity.

Sometimes called cape gooseberries, winter cherries, or husk tomatoes, ground cherries are small yellow fruits with a papery husk. Their taste has been described as something between a tomato and pineapple, which makes them great as ingredients in desserts, salads, jams, or even plain.

Ground cherries sometimes make their way into U.S. farmers markets where they sell like hotcakes. In order to make them more available to consumers, the orphan crop would have to be grown more easily and with a much higher yield. Typically, we’d have to wait for many years to completely domesticate the plant. However, researchers at the Boyce Thompson Institute decided to take a shortcut.

Researchers managed to bring the ground cherry from almost wild to almost domesticated in a matter of years. Credit: Sebastian Soyk.

Researchers managed to bring the ground cherry from almost wild to almost domesticated in a matter of years. Credit: Sebastian Soyk.

The team wanted to make the plant’s weedy shape more compact, give it larger fruits and more prolific flowers. First, they sequenced the ground cherry’s genome, which enabled them to identify the genes responsible for the crop’s undesirable traits. Then, the researchers used the controversial gene editing tool CRISPR to manipulate these target genes.

“I firmly believe that with the right approach, the groundcherry could become a major berry crop,” said Zachary Lippman, a plant scientist at Cold Spring Harbor Laboratory.

“I think we’re now at a place where the technology allows us to reach.”

Previously, the team manipulated the genomes of certain tomatoes — an approach which they applied to the ground cherry as well.

For now, the project is a proof of concept — the first orphan crop in which CRISPR was applied to make it a ‘family’ crop that has a high yield. In the future, the researchers plan on fine-tuning their method to improve desired characteristics, such as fruit color and flavor. Of course, some conventional plant breeding will be required in order to make the ground cherry mainstream. How long this will take is not clear, as there is also the issue of navigating CRISPR’s intellectual property rights.

In any event, Lippman says that the study is all about “demonstrating what’s possible”, such that other researchers might be inspired to take on other orphan crops that have the potential for rapid domestication. This way, food security will be improved and our plates can be enriched with new flavors and tastes.

The findings appeared in the journal Nature Plants.

Dr. Amaia Arranz-Otaegui and Ali Shakaiteer sampling cereals in the Shubayqa area. Credit: Joe Roe.

Oldest bread found in Jordan predates agriculture by 4,000 years

In the Black Desert in northeastern Jordan, archaeologists have come across a crispy find — the charred remains of flatbread that was baked 14,400 years ago. This is effectively the oldest evidence of bread making found to date, suggesting that hunter-gatherers were perhaps inspired by their success with wild cereals to set off the agricultural revolution.

Dr. Amaia Arranz-Otaegui and Ali Shakaiteer sampling cereals in the Shubayqa area. Credit: Joe Roe.

Dr. Amaia Arranz-Otaegui and Ali Shakaiteer sampling cereals in the Shubayqa area. Credit: Joe Roe.

The team of researchers at the University of Copenhagen, University College London and the University of Cambridge analyzed 24 charred remains retrieved from fireplaces at a Natufian hunter-gatherer site known as Shubayqa 1.

These remains — which are very similar to flatbreads retrieved at Neolithic and Roman sites in Europe and Turkey — show that our ancestors had been using the wild counterparts of domesticated cereals, such as barley, einkorn, and oat, long before they domesticated the food crops. The wild cereals were ground, sieved, and kneaded prior to being baked into bread.

University of Copenhagen archaeobotanist Amaia Arranz Otaegui, first author of the new study, thinks that the production and cultivation of bread by hunter-gathers may have influenced the domestication of crops — something which the researchers hope to evaluate in the future.

One of the stone structures of the Shubayqa 1 site. The fireplace, where the bread was found, is in the middle. Credit: Alexis Pantos.

One of the stone structures of the Shubayqa 1 site. The fireplace, where the bread was found, is in the middle. Credit: Alexis Pantos.

Today, we’re used to plumpy tomatoes and plentiful corn but the wild varieties from whence they came were far less nurturing. For instance, the first bananas that were cultivated in Papua New Guinea used to be stocky and filled with seeds. By contrast, today’s bananas are smooth on the inside and seedless.

It took us more than 10,000 years of selective breeding in order to turn tiny kernels on tall grass into juicy corn on the cob. Imagine the determination, patience, and insight that was required of the first hunter-gatherers that made the huge leap to agriculture.

Carrots were biennial plants, meaning they took two years to complete their biological cycle. They also used to be very thin and frail. Today, carrots are tasty orange roots that are an annual winter crop. Credit: Flickr, macleaygrassman / Flickr, adactio.

Cabbage, broccoli, and kale all come from the same species, originally a wild mustard plant that is now often referred to as wild cabbage. The images speak for themselves. Credit: Wikipedia / Flickr, akaitor.

It’s hard to find someone who doesn’t love plump, juicy tomatoes. It’s even harder to picture how pathetic ancient tomatoes looked in comparison. These unmodified tomatoes were a lot smaller and darker, and resembled berries rather than the apple-shaped delight we all know today. Credit: Flickr, aris_gionis / Flickr, jeepersmedia.

 

“Natufian hunter-gatherers are of particular interest to us because they lived through a transitional period when people became more sedentary and their diet began to change. Flint sickle blades as well as ground stone tools found at Natufian sites in the Levant have long led archaeologists to suspect that people had begun to exploit plants in a different and perhaps more effective way. But the flatbread found at Shubayqa 1 is the earliest evidence of bread making recovered so far, and it shows that baking was invented before we had plant cultivation,” explained  Tobias Richter, who led the excavations at Shubayqa 1 in Jordan.

“So this evidence confirms some of our ideas. Indeed, it may be that the early and extremely time-consuming production of bread based on wild cereals may have been one of the key driving forces behind the later agricultural revolution where wild cereals were cultivated to provide more convenient sources of food,” he added.

The flatbread was identified after it was analyzed with electronic microscopy at the University College London, a method that allowed the researchers to locate the microstructures and particles of each charred food remain. This was less straightforward than it sounds, however. The researchers had to devise a new set of criteria for identifying flatbread, dough, and porridge-like products.

“Bread involves labor intensive processing which includes dehusking, grinding of cereals and kneading and baking. That it was produced before farming methods suggests it was seen as special, and the desire to make more of this special food probably contributed to the decision to begin to cultivate cereals. All of this relies on new methodological developments that allow us to identify the remains of bread from very small charred fragments using high magnification,” said Professor Dorian Fuller of the UCL Institute of Archaeology.

The findings were reported in the Proceedings of the National Academy of Sciences.

 

Sapiens-Neanderthal.

Man-made: we’ve domesticated our own species

They don’t make humans like they used to — quite literally. Living in social groups has led us to self-domesticate our species, new research finds.

Sapiens-Neanderthal.

Image credits hairymuseummatt / Wikimedia.

According to the hypothesis of human self-domestication, one of the forces that powered and steered our evolution was artificial selection in the cave, tribe, or hut. As we like to live with other people (and there’s no indication that this was ever different), prosocial behavior became valuable while antisocial behavior became increasingly shunned throughout our history — which created a selective evolutionary pressure for the former. New research, led by Professor Cedric Boeckx from the University of Barcelona, comes to offer genetic evidence in favor of this hypothesis.

The goodest boy is you!

Self-domestication is, in broad strokes, pretty much like regular domestication. Outwardly, it leads to a change in anatomical features — for example, imagine how dogs have adorable droopy ears and rounder heads while wolves have scary pointed ears and more angular heads. It also leads to behavioral changes, most notably a reduction in aggressiveness. The key difference, however, is that self-domestication of a species is done internally, if you will, without input from other species.

It’s a process that several researchers believe helped shaped modern humans, as well as other species, such as bonobos. Up to now, however, we lacked any genetic evidence to help prop this hypothesis up. Boeckx’s team worked with the genomes of our extinct (and wild) Neanderthal or Denisovan relatives to try and determine whether humans have, in fact, domesticated themselves.

They compared the genetic material from modern humans against that of several domesticated species and their wild type. The comparison aimed to find overlapping genes associated with domestication, such as those linked to docile behavior or gracile facial features. The researchers first compiled a list of domestication-associated genes in humans based on the comparison with Neanderthals and Denisovans, wild but extinct human species. Then, they compared this list to genomes from domesticated animals and their wild type.

According to their paper, there are a “statistically significant” number of domestication-associated genes which overlapped between modern humans and domestic animals, but not with their wild types. The team says these results strengthen the self-domestication hypothesis and help “shed light on […] our social instinct.”

“One reason that made scientists claim that humans are self-domesticated lied within our behavior: modern humans are docile and tolerant, like domesticated species, our cooperative abilities and pro-social behaviour are key features of our modern cognition,” says Boeckx.

“The second reason is that modern humans, when compared to Neanderthals, present a more gracile phenotype that resembles the one seen in domesticates when compared to their wild-type cousins,” added the expert.

[accordion style=”info”][accordion_item title=”What’s a phenotype?”]The phenotype represents an organism’s characteristics resulting from the interaction between its genes (genotype) and the environment. While the genotype dictates characteristics such as, let’s say, eye color, skin color, or maximum height, your phenotype is your actual height (a product of nutrition and genetics), your actual skin color (a product of exposure to sunlight and genetics), so on.

As a rule of thumb, the genotype is the digital blueprint and the phenotype is what actually came out on the production line.

[/accordion_item][/accordion]

The team used other statistical measures, including control species, to make sure they weren’t picking up on a fluke. Their aim was to rule out the possibility that these genes would randomly overlap between humans and domesticated animals, so they compared the genomes with species of great apes.

“We found that chimpanzees, orangutans and gorillas do not show a significant overlap of genes under positive selection with domesticates. Therefore, it seems there is a ‘special’ intersection between humans and domesticated species, and we take this to be evidence for self-domestication,” Boeckx said.

There’s still a lot of work left if we’re to tease out the physical, mental, and behavioral characteristics that these genes impart onto us. However, some broad lines can already be drawn, the team believes: Boeckx himself suspects that self-domestication might explain why humans are so ridiculously cooperative or our “special mode of cognition”,

The paper “Self-domestication in Homo sapiens: Insights from comparative genomics” has been published in the journal PLOS One.

Lion hunt art.

8,000 years old rock art in Saudi Arabia documents the earliest known use of dog leashes

Two ancient sites in Saudi Arabia have revealed an unexpected surprise, a new paper reports — the oldest known recording of dogs put on a leash. The 8,000-year-old images are etched into rock and depict humans and dogs working together in hunts before the widespread emergence of agriculture.

The carvings were discovered by Maria Guagnin, an archaeologist at the Max Planck Institute for the Science of Human History, at two rock-art sites in northwestern Saudi Arabia, Shuwaymis and Jubbah. The images, estimated to be around 8,000 years old, depict humans and dogs hunting side by side, and suggest that the two species were already ‘friends’ before farming took hold.

Shuwaymis and Jubbah.

The locations of Shuwaymis (bottom left) and Jubbah (bottom right).
Image credits Guagnin, M. et al., 2017, Journal of Anthropological Archaeology.

The two sites “contain the best and oldest examples of Neolithic rock art,” Saudi-Archaeology claims, adding that the region used to be rich “with people, flora, and wildlife” in the past. Those people left behind thousands of panels of rock-art showcasing their lives, society, and hunts, which Guagnin was documenting when she stumbled upon the unusual scenes.

Overall, she counted 156 depictions of dogs at Shuwaymis and 193 at Jubbah. The animals resemble today’s Canaan breed in appearance, Guagnin adds, with pricked ears, curled tails, and short snouts. They’re most often depicted helping bow-wielding human hunters take down prey including lions, ibexes, gazelles, or horses. The animals are clearly distinct from the hyenas and wolves depicted in other panels, Guagnin and her co-authors write.

Hunting panel 1.

Image credits Guagnin, M. et al., 2017, Journal of Anthropological Archaeology.

 

Canaan dog comparison.

Comparison between the Canaan breed and the dogs on the rock art panels.
Image credits Guagnin, M. et al., 2017, Journal of Anthropological Archaeology.

From what we know so far, dogs were domesticated from an ancestor of today’s gray wolf between 40,000 and 15,000 years ago. There’s still a lot of unknowns (and thus, room for debate) about how and where this domestication process took place, and how early humans and dogs interacted and co-existed. The panels described by Guagnin’s team will help to guide these discussions in the future. The images haven’t been directly dated so far, but the team estimates they date back between 8,000 and 9,000 years ago, to the pre-Neolothic era, before farming took root in the region.

The most interesting find, however, was that some of the hunting dogs taking seem to be leashed. The art depicts these dogs as tethered to the waist of hunters, quite the smart hack when you need two free hands to shoot arrows. It hasn’t been established why these dogs were leashed, but the team speculates that they may have been young dogs still undergoing training, old ones that could be injured in the thick of the hunt, or scent dogs that were too valuable to risk.

Lion hunt art.

Image credits Guagnin, M. et al., 2017, Journal of Anthropological Archaeology.

“This suggests not only are some human populations controlling their hunting dogs by the Pre-Neolithic, but that some dogs may perform different hunting tasks than others,” the paper explains.

“Some may be used only to track prey scents, while others are used to corral and attack prey, protect human hunters, or help haul meat back to camp.”

The hunting scenes represent the earliest known evidence of dog leashes in the archaeological record worldwide, the study claims. Furthermore, they push back the presence of domesticated dogs on the Arabian Peninsula to much earlier than we’d believed. Previously, the oldest dog remains found on the whole peninsula hailed from the 4th millennium B.C. in today’s Yemen, some 2-3 thousand years younger that the estimated age of the Shuwaymis and Jubbah panels.

The paper, “Pre-Neolithic evidence for dog-assisted hunting strategies in Arabia” has been published in the Journal of Anthropological Archaeology.

cat pet

Why some people love animals while others couldn’t care less

cat pet

Credit: Pixabay.

The recent popularity of “designer” dogs, cats, micro-pigs and other pets may seem to suggest that pet keeping is no more than a fad. Indeed, it is often assumed that pets are a Western affectation, a weird relic of the working animals kept by communities of the past.

About half of the households in Britain alone include some kind of pet; roughly 10m of those are dogs while cats make up another 10m. Pets cost time and money, and nowadays bring little in the way of material benefits. But during the 2008 financial crisis, spending on pets remained almost unaffected, which suggests that for most owners pets are not a luxury but an integral and deeply loved part of the family.

Some people are into pets, however, while others simply aren’t interested. Why is this the case? It is highly probable that our desire for the company of animals actually goes back tens of thousands of years and has played an important part in our evolution. If so, then genetics might help explain why a love of animals is something some people just don’t get.

The health question

In recent times, much attention has been devoted to the notion that keeping a dog (or possibly a cat) can benefit the owner’s health in multiple ways – reducing the risk of heart disease, combating loneliness, and alleviating depression and the symptoms of depression and dementia.

As I explore in my new book, there are two problems with these claims. First, there are a similar number of studies that suggest that pets have no or even a slight negative impact on health. Second, pet owners don’t live any longer than those who have never entertained the idea of having an animal about the house, which they should if the claims were true. And even if they were real, these supposed health benefits only apply to today’s stressed urbanites, not their hunter-gatherer ancestors, so they cannot be considered as the reason that we began keeping pets in the first place.

The urge to bring animals into our homes is so widespread that it’s tempting to think of it as a universal feature of human nature, but not all societies have a tradition of pet-keeping. Even in the West there are plenty of people who feel no particular affinity for animals, whether pets or no.

The pet-keeping habit often runs in families: this was once ascribed to children coming to imitate their parents’ lifestyles when they leave home, but recent research has suggested that it also has a genetic basis. Some people, whatever their upbringing, seem predisposed to seek out the company of animals, others less so.

So the genes that promote pet-keeping may be unique to humans, but they are not universal, suggesting that in the past some societies or individuals – but not all – thrived due to an instinctive rapport with animals.

Pet DNA

pig livestock

Credit: Pixabay.

The DNA of today’s domesticated animals reveals that each species separated from its wild counterpart between 15,000 and 5,000 years ago, in the late Palaeolithic and Neolithic periods. Yes, this was also when we started breeding livestock. But it is not easy to see how this could have been achieved if those first dogs, cats, cattle and pigs were treated as mere commodities.

If this were so, the technologies available would have been inadequate to prevent unwanted interbreeding of domestic and wild stock, which in the early stages would have had ready access to one another, endlessly diluting the genes for “tameness” and thus slowing further domestication to a crawl – or even reversing it. Also, periods of famine would also have encouraged the slaughter of the breeding stock, locally wiping out the “tame” genes entirely.

But if at least some of these early domestic animals had been treated as pets, physical containment within human habitations would have prevented wild males from having their way with domesticated females; special social status, as afforded to some extant hunter-gatherer pets, would have inhibited their consumption as food. Kept isolated in these ways, the new semi-domesticated animals would have been able to evolve away from their ancestors’ wild ways, and become the pliable beasts we know today.

The very same genes which today predispose some people to take on their first cat or dog would have spread among those early farmers. Groups which included people with empathy for animals and an understanding of animal husbandry would have flourished at the expense of those without, who would have had to continue to rely on hunting to obtain meat. Why doesn’t everyone feel the same way? Probably because at some point in history the alternative strategies of stealing domestic animals or enslaving their human carers became viable.

There’s a final twist to this story: recent studies have shown that affection for pets goes hand-in-hand with concern for the natural world. It seems that people can be roughly divided into those that feel little affinity for animals or the environment, and those who are predisposed to delight in both, adopting pet-keeping as one of the few available outlets in today’s urbanised society.

The ConversationAs such, pets may help us to reconnect with the world of nature from which we evolved.

By John Bradshaw, Visiting Fellow in Anthrozoology, University of Bristol

This article was originally published on The Conversation. Read the original article.

Russian geneticist breeds the first domesticated foxes and I want one

A Russian geneticist has done something that took our ancestors thousands of years in just five decades. By selectively breeding hundreds of Vulpes vulpes foxes over multiple generations, Dmitry K. Belyaev has created a never-before-seen pet: the domesticated fox.

Image credits Neil McIntosh / Flickr.

On an unassuming farm in Novosibirsk, a new breed of pets is poised to take the world’s hearts by storm. In his quest of recreating the process by which ancient humans turned wild dogs from predators to “man’s best friend’ to learn about domestication, Russian geneticist Dmitry K. Belyaev has created the world’s first docile foxes.

In essence, what he did was husbandry or artificial selection. By basing future generations on individuals who exhibited one desired trait the strongest, he gradually added to the tameness of the animal — this was the same process our ancestors used to increase their crops’ and livestock’s yield and hardiness. The process was pretty straightforward but time-consuming. Belyaev visited fur farms around Russia in the late 1950’s and selected the friendliest foxes he could find. He bred successive generations starting from this stock, selecting the tamest individuals each time.

In the early 2000s, almost all of the foxes on Belyaev’s farm show surprising changes in behavior, reported Lucy Jones for the BBC.

Cuddly, friendly little vixens

Foxes are considered especially hard to tame, but these ones on the farm seem to enjoy their time with people. They acted more like dogs than what we’d expect from a fox — things such as wagging their tails or perking up in the presence of a human. The foxes didn’t show any of the aggressive or skittish nature we expect in wild animals. On the contrary, they would seek out people to pet them and even lick their handler’s face — and you can’t really get more “dog” than that.

Belyaev said this all happens without any sort of training on his part. The only thing he did was to select for the foxes that interacted with humans the best.

“They’re genetically designed to crave human contact,” said Ceiridwen Terrill, a professor of Science Writing and Environmental Journalism at Concordia University in Portland who visited the farm and got to pet the foxes, for NPR.

“So that fox loved having its belly scratched.”

The foxes also started looking tamer over time: their ears got floppier, they developed shorter legs, tails, snouts, and their skulls widened. Their breeding patterns have also changed, and the foxes now mated out of season and had on average one more offspring per litter. In a 2009 paper, Lyudmila Trut of the Institute of Cytology and Genetics at the Russian Academy of Sciences, who now oversees the farm, says this is likely caused by neurological and endocrinological changes promoted through selective breeding.

The paper found that compared to wild foxes, Belyaev’s pets show the difference in brain chemistry. Their adrenal glands are less active but they have higher levels of serotonin, which helps mediate aggressive behavior, Trut writes. The droopy ears could be explained by their slower adrenal system, BBC writes, and the selected hormonal differences could also inadvertently promote physical differences. Dogs likely went through much the same process over the course of hundreds of generations as they gradually adapted to living with us.

The experiment confirms our theories regarding domestication. Not only the fact that we can bend a species evolutionary course in our favor, but also that the process affects more than their behavior. Domestication alters a species looks, inner workings, and the cycles they live their lives by.

 

Turns out goats and dogs aren’t that different when communicating with humans

The derpy goat might rival a dog’s ability to communicate with humans, a new study found. This adds to previous research showing that these animals are good problem-solvers and have excellent long-term memory, suggesting these ruminants are more intelligent than they appear.

This guy learned how to bleat fluently in several languages.
Image credits wikimedia user EnderWikiTX.

Goats are the first domesticated animals we know of, with evidence of their husbandry stretching as far as 10,000 years ago according to lead author Dr. Alan McElligott from Queen Mary University of London’s Department of Biological and Experimental Psychology. During all this time they’ve built a reputation of eating virtually anything and getting stuck in weird places in their unending quest for food — hardly what you’d expect from an intelligent animal.

But their wily ways might hide a sharper mind than we give them credit for. McElliogott’s team found that goats employ human communication behaviours very similar to the ones dogs rely on. The researchers trained the animals to remove a lid from a box with a tasty reward inside. After the goats got the hang of it, the team made the rewards inaccessible and recorded the animals’ reactions towards an experimenter supervising the test — who was either facing the animal or had his back to it.

https://www.youtube.com/watch?v=5CJgWjhW2CE

When the animals found they couldn’t reach the treat, they shifted their gaze between the box and their human experimenters, similar to what dogs do when they need help. The ruminants also seemed to understand when communication was viable or not: they looked towards a person facing them more often and for longer periods of time compared to an experimenter facing away from them.

Average time for (a) gaze latencies, (b) gaze durations, (c) gaze frequencies, (d) latencies until first gaze alternation and (e) frequencies of gaze alternations towards either Experimenter 1 or Experimenter 2. Dark grey bars indicate forward looking group of experimenters, and light grey bars the ones facing away. Asterisk indicates significant differences between groups.
Image provided by authors.

“Goats gaze at humans in the same way as dogs do when asking for a treat that is out of reach, for example. Our results provide strong evidence for complex communication directed at humans in a species that was domesticated primarily for agricultural production, and show similarities with animals bred to become pets or working animals, such as dogs and horses,” said first author Dr. Christian Nawroth.

If you look at dogs, domestication came with a decrease in foraging skills and social complexity, but their brains adapted so they can perceive information from humans. This makes sense for dogs as they are bred to be companion animals, but not so much for goats — they have always been bred almost exclusively for agricultural purposes. The findings of this study thus suggest that domestication has more far-reaching implications on animals’ psychology than previously believed.

“From our earlier research, we already know that goats are smarter than their reputation suggests, but these results show how they can communicate and interact with their human handlers even though they were not domesticated as pets or working animals.”

The researchers hope their findings will help farmers better understand their animals and lead to a general improvement in animal welfare.

The full paper, titled “Goats display audience-dependent human-directed gazing behaviour in a problem-solving task” has been published online in the journal Biology Letters.

dog evolution

Dogs may have been first domesticated in Nepal and Mongolia

It probably took a bit of convincing for man to turn wolves into dogs through domestication. At least this is not settled for debate: dogs branched from Eurasian grey wolves some 15,000 years ago. What’s less clear is where did this first happen. After embarking on a huge study which led them to analyze the genetic markup of hundreds of dog breeds, Adam Boyko at Cornell University thinks he’s finally got an answer: dogs were first domesticated in Central Asia, or in modern day Nepal and Mongolia.

dog evolution

Image: esdaw.eu

Boyko and colleagues swabbed DNA samples from  4,500 dogs belonging to 161 breeds, but also from 549 “village dogs” – the strays, genetically impure and wild variety of dogs. In total, dogs from 38 countries had their DNA sequenced. This analysis suggests that  East Asia, India and South-West Asia had the highest level of genetic diversity, giving confidence that dogs originated in what is now Nepal and Mongolia.

This far from the final word yet. Previous studies posited that dogs actually first appeared in Europe, others suggest Siberia as a more likely candidate. Boyko’s work, however, bears the largest population sample by far for such an investigation.  “We cannot rule out the possibility that dogs were domesticated elsewhere and subsequently, either through migration or a separate domestication event,” Boyko said.

Ancient cave painting showing a hunter and his dog (undated). Image: ScienceaGoGO

Ancient cave painting showing a hunter and his dog (undated). Image: ScienceaGoGO

The earliest archaeological evidence of canine domestication can be traced to the Natufian Grave, (c. 12,000 BCE) discovered in Ein Mallaha, Israel, in which an old man was buried with a puppy. Other ancient findings suggest that dogs were ubiquitously seen as guardians and faithful companions, no matter the culture or time – just like today. For instance, in the Epic of Gilgamesh from ancient Mesopotamia one scene depicts the goddess Ishtar traveling with seven prized dogs.

“The dog (Sumerian name, ur-gi; Semitic name, Kalbu) was one of the earliest domestic animals and served primarily to protect herds and dwellings against enemies. Despite the fact that dogs roamed freely in the cities, the dog in the ancient Orient was at all times generally bound to a single master and was cared for by him. Of course, the dog was also a carrion eater, and in the villages it provided the same service as hyenas and jackals. As far as we can tell, there were only two main breeds of dog: large greyhounds which were used primarily in hunting, and very strong dogs (on the order of Danes and mastiffs), which in the ancient Orient were more than a match for the generally smaller wolves and, for that reason, were especially suitable as herd dogs. The sources distinguish numerous sub-breeds, but we can only partially identify these. The dog was often the companion of gods of therapeutics. Although the expression `vicious dog’ occurred, `dog’ as a derogatory term was little used (91),” notes famed historian  Wolfram Von Soden.

In Egypt, dogs were valued as part of the family and, when a dog would die, the family, if they could afford to, would have the dog mummified with as much care as they would pay for a human member of the family. In ancient Greek literature, the first mentions of dogs come under the three-headed dog Cerberus who guarded the gates of Hades. Dogs were the earliest animals domesticated in China (c. 12,000 BCE) along with pigs and were used in hunting and kept as companions. The blood of a dog was an important component in sealing oaths and swearing allegiances because dogs were thought to have been given to humans as a gift from heaven and so their blood was sacred. Today, the Chinese still spill the blood of dogs, but for less ritualistic purposes (i.e. feeding). Ancient Aztecs actually thought dogs predate humans. Moreover,  the souls of those who died without proper burial, such as those who drowned or were lost in battle or died alone on a hunt, were found by spirit dogs who would ensure their safe passage to the afterlife.

 

Cat domestication traced to Chinese farmers – 5.300 years ago

This is the cat
That killed the rat
That ate the malt

They say it’s easy to train a cat only to do whatever it wants – but cats have come a long way since their wilderness days. Thousands of years before they were immortalized in this lovely English lullaby, cats were doing just fine alongside Chinese farmers, a forthcoming study in the Proceedings of the National Academy of Sciences has confirmed.

Wildcat. (Credit: © XK / Fotolia)

“At least three different lines of scientific inquiry allow us to tell a story about cat domestication that is reminiscent of the old ‘house that Jack built’ nursery rhyme,” said study co-author Fiona Marshall, PhD, a professor of archaeology in Arts & Sciences at Washington University in St. Louis. Our data suggest that cats were attracted to ancient farming villages by small animals, such as rodents that were living on the grain that the farmers grew, ate and stored.”

Strangely enough, this is the first study ever to provide direct evidence of cat domestication. Cat remains are rarely found in archaeological sites, and very little is known about how they became domesticated. Since they were worshiped (more or less) in ancient Egypt, it was thought that they were initially domesticated there.

“Results of this study show that the village of Quanhucun was a source of food for the cats 5,300 years ago, and the relationship between humans and cats was commensal, or advantageous for the cats,” Marshall said. “Even if these cats were not yet domesticated, our evidence confirms that they lived in close proximity to farmers, and that the relationship had mutual benefits.”

Recent studies show that the human-cat connection could go even further, as a wild cat was found buried with a human nearly 10,000 years ago in Cyprus. Since rodents were a relatively common sight in ancient human societies, it was thought that cats were attracted to them, and, indirectly, to humans. However, little evidence documents this idea.

Using radiocarbon dating and isotopic analyses of carbon and nitrogen traces in the bones of cats, dogs, deer and other wildlife unearthed near Quanhucan, researchers showed that a breed of once-wild cats carved found another niche for them in the Chinese agrarian society. The carbon isotopes showed that rodents, domestic dogs and pigs from the ancient village were eating millet, but deer were not. Also, carbon and nitrogen isotopes show that cats were feasting on animals who ate millet – probably rodents, since it seems very unlikely that cats ate dogs and pigs.

Other clues were also found: one of the cats was aged, showing that it survived well adapting to the human society. Another one ate fewer animals and more millet than expected, which seems to suggest that it was cared for, or that it scavenged human food instead of hunting.

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The above story is based on materials provided by Washington University in St. Louis

Cats recognise their owners’ voices but never evolved to care, questionable study shows

Japanese researchers showed that cats are able to recognize their owners’ voices from other voices, but because they domesticated themselves, they never really needed to take notice. The study supports the idea that while cats are often kept as pets, they are beholden to no one.

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photo credit: katherine lynn

Reserchers Atsuko Saito and Kazutaka Shinozuka tested twenty housecats in their own homes; they waited until their owners were out of sight, then played them recordings of three strangers calling out their names, followed by their owners, and then another stranger. They then their responses by measuring ear, tail and head movement, vocalization, eye dilation and ‘displacement’ – shifting their paws to move.

Results showed that cats did showed some degree of response whenever their name is called, they were most receptive when their owners called them out. However, they declined to move when called by any of the volunteers.

“These results indicate that cats do not actively respond with communicative behavior to owners who are calling them from out of sight, even though they can distinguish their owners’ voices,” write Saito and Shinozuka. “This cat–owner relationship is in contrast to that with dogs.”

Personally, I’m not totally sold on this type of study. My cat is very receptive when I call him, he comes at least 9 times out of 10 – I tested this a few times today already. My mother’s cat also does the same thing, and even my girlfriend’s cat, who’s 6 months old does it (we’re animal lovers, don’t judge us). So I don’t really know what to say about the validity of this study in a broader, general context.

photo credit: DDFic

photo credit: DDFic

But one thing’s for sure – cats are generally less receptive to calls than dogs; the Japanese researchers suggest that the reason for cats’ unresponsive behaviour might be traced back to the early domestication of the species.

“Historically speaking, cats, unlike dogs, have not been domesticated to obey humans’ orders. Rather, they seem to take the initiative in human–cat interaction.” This is in contrast to the history of dogs and humans, where the former has been bred over thousands of years to respond to orders and commands. Cats, it seems, never needed to learn.

However, the paper also notes that dog and cat owners love their pets just as much:

“Dogs are perceived by their owners as being more affectionate than cats […] dog owners and cat owners do not differ significantly in their reported attachment level to their pets”.

But what I really found funny is the last sentence in the study: “the behavioural aspect of cats that cause their owners to become attached to them are still undetermined.” So basically, they’re saying they have no idea why anyone would love cats.

Horse

Horse domestication origins revealed after extensive gene study

HorseHorses are arguably one of the most helpful animals man has ever managed to domesticate. At first they were used as source of meat and milk, but it was soon evident that horses were a lot more suited as labor animals than as a direct food medium. Important agricultural advancements were made possible thanks to horses, and due to their reliable nature, horses practically moved the work for thousands of years prior to the introduction of automobiles. Trade, infrastructure, and, of course, war efforts were profoundly interlinked to horses. When and where were horses first domesticated, however, has been a question scientists have been intrigued with for many years.

A new study by scientists at the University of Cambridge finally sheds light on the origin of horse domestication, after an extensive genetic research revealed horses were domesticated 6,000 years ago on the grasslands of Ukraine, southwest Russia and west Kazakhstan.

An extensive genetic database of over 300 Eurasian horses was used to trace the origins of domestic breeds, be it warm, cold or hot blood. This comprehensive genetic data was then fed into computer models developed to look at different scenarios for domestication. Researchers determined that the domestic horse’s common ancestor, Equus ferus, inhabited the western Eurasian steppes around 160,000 years ago. Apparently, evidence suggests that wild mares were used to mate with existing domesticated horses, since breeding is far from easy in captivity.

“Our research clearly shows that the original founder population of domestic horses was established in the western Eurasian Steppe, an area where the earliest archaeological evidence for domesticated horses has been found,” said Vera Warmuth, from the University of Cambridge’s Department of Zoology.

“The spread of horse domestication differed from that of many other domestic animal species, in that spreading herds were augmented with local wild horses on an unprecedented scale. If these restocking events involved mainly wild mares, we can explain the large number of female lineages in the domestic horse gene pool without having to invoke multiple domestication origins.”

The findings were reported in the journal PNAS.